582
FNCA52 TJSJ 170820
FWFSJU
FIRE WEATHER PLANNING FORECAST FOR PUERTO RICO
NATIONAL WEATHER SERVICE SAN JUAN PR
420 AM AST FRI JUL 17 2026
DISCUSSION
ELEVATED FIRE WEATHER CONDITIONS WILL PERSIST TODAY ACROSS PORTIONS
OF PUERTO RICO, PARTICULARLY ALONG THE SOUTHERN COASTAL PLAINS AND
ADJACENT LOWER ELEVATIONS. DESPITE PATCHES OF LOW-LEVEL MOISTURE
MOVING ACROSS THE REGION, RELATIVE HUMIDITY VALUES WILL CONTINUE TO
DROP INTO THE UPPER 40S TO LOWER 50S THIS AFTERNOON, WHILE BREEZY
EASTERLY WINDS OF 15 TO 20 MPH WITH HIGHER GUSTS PROMOTE FAVORABLE
CONDITIONS FOR RAPID FIRE SPREAD.
RECENT OBSERVATIONS INDICATE THAT CRITICALLY DRY FUELS REMAIN IN
PLACE, WITH KBDI VALUES EXCEEDING 700 ACROSS MUCH OF PUERTO RICO AND
PERSISTENT RAINFALL DEFICITS MAINTAINING VEGETATION STRESS. ALTHOUGH
LOCALIZED SHOWERS ARE EXPECTED EACH AFTERNOON, WIDESPREAD BENEFICIAL
RAINFALL IS NOT ANTICIPATED THROUGH THE WEEKEND, AND LITTLE
IMPROVEMENT IN FIRE WEATHER CONDITIONS IS EXPECTED. THEREFORE, AN
ELEVATED FIRE DANGER WILL CONTINUE ACROSS SOUTHERN PUERTO RICO,
WHERE A FIRE DANGER STATEMENT IS IN EFFECT.
PRZ014-172015-
SOUTHEAST COASTAL PLAINS-
420 AM AST FRI JUL 17 2026
TODAY TONIGHT SAT
CLOUD COVER MCLEAR MCLEAR MCLEAR
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 10 10 20
TEMP (24H TREND) 92 (+1) 74 (-2) 92
RH % (24H TREND) 45 (-6) 86 (+5) 45
WIND 20FT/EARLY(MPH) E 13 G21 E 12 E 14 G23
WIND 20FT/LATE(MPH) E 14 G23 NE 10 E 16 G24
MIXING HGT(FT-AGL/MSL)5510 5430
TRANSPORT WND (MPH) E 16 E 18
VENT RATE (KT-FT) 77140 86880
DISPERSION 5 5
DSI 6 4 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ015-172015-
SOUTHERN HILLS-
420 AM AST FRI JUL 17 2026
TODAY TONIGHT SAT
CLOUD COVER MCLEAR MCLEAR PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 20 10 20
TEMP (24H TREND) 89 (+3) 70 (-3) 90
RH % (24H TREND) 55 (-7) 96 (+6) 55
WIND 20FT/EARLY(MPH) E 13 E 13 E 14
WIND 20FT/LATE(MPH) E 13 E 12 E 14
MIXING HGT(FT-AGL/MSL)5890 5780
TRANSPORT WND (MPH) E 15 E 17
VENT RATE (KT-FT) 76570 86700
DISPERSION 5 5
DSI 6 3 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ016-172015-
NORTH COASTAL PLAINS-
420 AM AST FRI JUL 17 2026
TODAY TONIGHT SAT
CLOUD COVER PCLDY MCLEAR PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 30 0 20
TEMP (24H TREND) 91 (+1) 76 (0) 90
RH % (24H TREND) 57 (-6) 91 (0) 58
WIND 20FT/EARLY(MPH) E 14 E 20 E 18
WIND 20FT/LATE(MPH) E 23 E 14 E 23
MIXING HGT(FT-AGL/MSL)5860 5290
TRANSPORT WND (MPH) E 17 E 21
VENT RATE (KT-FT) 87900 95220
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ017-172015-
NORTHERN HILLS-
420 AM AST FRI JUL 17 2026
TODAY TONIGHT SAT
CLOUD COVER PCLDY MCLEAR PCLDY
PRECIP TYPE SHOWERS NONE SHOWERS
CHANCE PRECIP (%) 40 0 20
TEMP (24H TREND) 90 (+1) 71 (-2) 90
RH % (24H TREND) 58 (-3) 96 (+1) 59
WIND 20FT/EARLY(MPH) E 12 E 17 E 16
WIND 20FT/LATE(MPH) E 19 E 12 E 20
MIXING HGT(FT-AGL/MSL)6970 6420
TRANSPORT WND (MPH) E 13 E 16
VENT RATE (KT-FT) 76670 89880
DISPERSION 5 5
DSI 6 4 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ018-172015-
WEST COAST-
420 AM AST FRI JUL 17 2026
TODAY TONIGHT SAT
CLOUD COVER PCLDY MCLEAR PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 30 40 40
TEMP (24H TREND) 93 (+1) 75 (+1) 93
RH % (24H TREND) 56 (-4) 90 (-4) 58
WIND 20FT/EARLY(MPH) E 13 E 11 E 14
WIND 20FT/LATE(MPH) E 13 E 14 E 16
MIXING HGT(FT-AGL/MSL)4810 4460
TRANSPORT WND (MPH) E 12 E 10
VENT RATE (KT-FT) 48100 40140
DISPERSION 5 5
DSI 6 3 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ019-172015-
EASTERN INTERIOR-
420 AM AST FRI JUL 17 2026
TODAY TONIGHT SAT
CLOUD COVER PCLDY PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 30 20 20
TEMP (24H TREND) 89 (+2) 73 (-2) 89
RH % (24H TREND) 56 (-7) 96 (+4) 58
WIND 20FT/EARLY(MPH) E 14 E 13 E 14
WIND 20FT/LATE(MPH) E 13 E 13 E 14
MIXING HGT(FT-AGL/MSL)6490 6300
TRANSPORT WND (MPH) E 16 E 17
VENT RATE (KT-FT) 90860 94500
DISPERSION 5 5
DSI 6 4 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ022-172015-
LUQUILLO MOUNTAIN RANGE-
420 AM AST FRI JUL 17 2026
TODAY TONIGHT SAT
CLOUD COVER PCLDY PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 30 30 20
TEMP (24H TREND) 84 (+3) 70 (-2) 84
RH % (24H TREND) 66 (-8) 99 (+3) 66
WIND 20FT/EARLY(MPH) E 12 E 12 E 13
WIND 20FT/LATE(MPH) E 12 E 11 E 13
MIXING HGT(FT-AGL/MSL)5060 5330
TRANSPORT WND (MPH) E 17 E 18
VENT RATE (KT-FT) 75900 85280
DISPERSION 5 5
DSI 6 5 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ023-172015-
CENTRAL MOUNTAIN RANGE-
420 AM AST FRI JUL 17 2026
TODAY TONIGHT SAT
CLOUD COVER PCLDY MCLEAR PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 30 30 20
TEMP (24H TREND) 88 (+4) 68 (-2) 89
RH % (24H TREND) 60 (-5) 97 (+2) 60
WIND 20FT/EARLY(MPH) E 10 E 10 E 10
WIND 20FT/LATE(MPH) E 11 E 10 E 13
MIXING HGT(FT-AGL/MSL)7300 7470
TRANSPORT WND (MPH) E 12 E 12
VENT RATE (KT-FT) 73000 74700
DISPERSION 5 5
DSI 6 2 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ024-172015-
CAYEY MOUNTAIN RANGE-
420 AM AST FRI JUL 17 2026
TODAY TONIGHT SAT
CLOUD COVER PCLDY PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 30 20 20
TEMP (24H TREND) 85 (+2) 71 (-1) 85
RH % (24H TREND) 64 (-5) 99 (+2) 64
WIND 20FT/EARLY(MPH) E 12 E 12 E 13
WIND 20FT/LATE(MPH) E 12 E 10 E 13
MIXING HGT(FT-AGL/MSL)5640 5600
TRANSPORT WND (MPH) E 16 E 18
VENT RATE (KT-FT) 78960 89600
DISPERSION 5 5
DSI 6 4 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ025-172015-
VIEQUES-
420 AM AST FRI JUL 17 2026
TODAY TONIGHT SAT
CLOUD COVER MCLEAR MCLEAR PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 10 10 20
TEMP (24H TREND) 89 (+1) 79 (0) 90
RH % (24H TREND) 58 (-5) 84 (+1) 58
WIND 20FT/EARLY(MPH) E 17 E 17 E 19
WIND 20FT/LATE(MPH) E 16 E 17 E 16
MIXING HGT(FT-AGL/MSL)3790 3300
TRANSPORT WND (MPH) E 20 E 21
VENT RATE (KT-FT) 64430 59400
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ026-172015-
CULEBRA-
420 AM AST FRI JUL 17 2026
TODAY TONIGHT SAT
CLOUD COVER MCLEAR MCLEAR MCLEAR
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 10 10 20
TEMP (24H TREND) 91 (+3) 79 (-1) 91
RH % (24H TREND) 59 (-9) 88 (+4) 58
WIND 20FT/EARLY(MPH) E 17 E 17 E 18
WIND 20FT/LATE(MPH) E 16 E 17 E 16
MIXING HGT(FT-AGL/MSL)3800 3360
TRANSPORT WND (MPH) E 20 E 21
VENT RATE (KT-FT) 64600 60480
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ027-172015-
SOUTHWEST COASTAL PLAINS AND MONA ISLAND-
420 AM AST FRI JUL 17 2026
TODAY TONIGHT SAT
CLOUD COVER MCLEAR MCLEAR MCLEAR
PRECIP TYPE SHOWERS NONE SHOWERS
CHANCE PRECIP (%) 10 0 20
TEMP (24H TREND) 93 (+2) 76 (0) 92
RH % (24H TREND) 49 (-3) 82 (-1) 48
WIND 20FT/EARLY(MPH) E 16 G24 E 13 E 17 G26
WIND 20FT/LATE(MPH) SE 17 G25 E 12 SE 19 G28
MIXING HGT(FT-AGL/MSL)5080 4960
TRANSPORT WND (MPH) E 21 E 20
VENT RATE (KT-FT) 91440 84320
DISPERSION 5 5
DSI 6 4 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
VIZ001-172015-
SAINT THOMAS AND SAINT JOHN-
420 AM AST FRI JUL 17 2026
TODAY TONIGHT SAT
CLOUD COVER MCLEAR MCLEAR MCLEAR
PRECIP TYPE SHOWERS NONE SHOWERS
CHANCE PRECIP (%) 10 0 10
TEMP (24H TREND) 88 (+2) 78 (-1) 88
RH % (24H TREND) 61 (-8) 88 (+3) 59
WIND 20FT/EARLY(MPH) E 17 E 18 E 19
WIND 20FT/LATE(MPH) E 16 E 18 E 17
MIXING HGT(FT-AGL/MSL)3690 3440
TRANSPORT WND (MPH) E 21 E 24
VENT RATE (KT-FT) 66420 72240
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
VIZ002-172015-
ST CROIX-
420 AM AST FRI JUL 17 2026
TODAY TONIGHT SAT
CLOUD COVER MCLEAR MCLEAR MCLEAR
PRECIP TYPE SHOWERS NONE NONE
CHANCE PRECIP (%) 10 0 0
TEMP (24H TREND) 90 (+3) 79 (0) 91
RH % (24H TREND) 59 (-9) 87 (+1) 58
WIND 20FT/EARLY(MPH) E 17 E 17 E 18
WIND 20FT/LATE(MPH) E 17 E 18 E 17
MIXING HGT(FT-AGL/MSL)4940 5420
TRANSPORT WND (MPH) E 22 E 23
VENT RATE (KT-FT) 93860 108400
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
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